Bad Memories Easier to Remember

Aug. 29, 2007 -- There may be a good reason why most people remember exactly
what they were doing when tragedies happen, like the JFK assassination or Sept.
11th, but have a hard time remembering birthdays and anniversaries. It turns
out that remembering the bad times just comes more naturally.

A new study suggests that we recall bad memories more easily and in greater
detail than good ones for perhaps evolutionary reasons.

Researchers say negative emotions like fear and sadness trigger increased
activity in a part of the brain linked to memories. These emotionally charged
memories are preserved in greater detail than happy or more neutral memories,
but they may also be subject to distortion.

For example, eyewitnesses to a shooting often report seeing the gun vividly,
but they may not remember precise details of their surroundings.

“These benefits make sense within an evolutionary framework,” writes
researcher Elizabeth Kensinger of Boston College in a review of research on the
topic in Current Directions in Psychological Science. “It is logical
that attention would be focused on potentially threatening information.”

Bad Memories Linger

Researchers say studies using functional magnetic resonance imaging (fMRI)
have shown negative events stimulate activity in emotion-processing regions of
the brain, such as the orbitofrontal cortex and the amygdala.

The more these emotional centers are activated by an event, the more likely
an individual is to remember specific details linked to the emotional aspect of
the event, like the appearance of the gun, and perhaps less likely to remember
more mundane details like a street address.

Researchers say this technique of preserving bad memories may have evolved
as an evolutionary tactic to protect against future life-threatening or
negative events.

They say more studies how we remember bad memories are needed to help
understand posttraumatic stress disorder as well as evaluate the reliability of
eyewitness testimony.